1. Field of the Invention PA0 2. Prior Art
The present invention relates to a high-speed filling and packaging apparatus for manufacturing parallelepiped package containers filled with fluid content such as juice and a cutting apparatus employed by this filling and packaging apparatus.
There is known a conventional filling and packaging apparatus comprising an unwinder for supporting a web serving as a packing material (hereinafter referred to simply as packaging material web) in an rolled state, a unwinding apparatus for unwinding the web in order from the unwinder, a tube-forming apparatus for forming the unwound web in a tubular shape after sterilizing it, a liquid supply pipe for filling fluid content in the packaging material web which was formed in the tubular shape, and a container-forming apparatus for laterally sealing the web and cutting sealed parts of the web to continuously form pillow-shaped containers each having a rectangular shape in cross section while downwardly supplying the tube filled with the fluid content by the length corresponding to one container, and a container shaping apparatus for bending each end part of the pillow-shaped containers which are separated into individual ones to shape each pillow-shaped container in a parallelepiped container to be finally obtained (as disclosed in JP-A 58-193206 and JP-A 61-93010).
In the conventional filling and packaging apparatus, two pairs of lateral seal bars are vertically alternately movable and are provided with a pressure application mechanism for laterally sealing and cutting a packaging material web formed in a tubular shape. As shown in FIG. 1, the pressure application mechanism comprises a heating mechanism called inductors 2 for melting a resin of the web 1, a cooling mechanism such as pipes 3 of cooling refrigerant for quickly cooling the melted resin, and a cutting mechanism having a cutter blade 4 for accurately cutting and separating sealed parts of the laterally sealed package containers into individual ones. When the containers are formed using the lateral seal bars, heating, cooling and cutting processes can be performed continuously and integrally, and timing between these processes can be adjusted and controlled very easily, thereby achieving an excellent method of manufacturing the containers.
A capacity of the filling and packaging apparatus of this type for manufacturing containers per hour depends on the speed involved in a pressure application process in the lateral seal bars provided with heating, cooling and cutting mechanisms, and it takes about 0.6 second for performing the pressure application process corresponding to the length of one container. That is, the maximum manufacturing capacity per hour which has been conventionally performed is obtained by dividing one hour (3600 seconds) by 0.6 second per piece, namely, the quotient of 6000 pieces of containers. The apparatus having such a manufacturing capacity has been known as a high-speed filling and packaging apparatus.
In the pressure application process, it takes about 0.28 second for heating, 0.15 to 0.17 second for cooling and 0.15 to 0.17 second for cutting (0.6 second in total). The times involved in heating, cooling and cutting is required respectively to the minimum. For example, if the heating time is less than 0.28 second, a resin serving as a laminating material of the packaging material web is not sufficiently melted to make the sealing complete. If the cooling time is less than 0.15 to 0.17 second, the melted resin is cut in a state where it is not solidified, which caused an inconvenience that the sealing becomes incomplete and the melted resin is stuck to the cutter blade 4 to obstruct the succeeding cutting process. Further, a mechanical cutting by the cutter blade 4 takes 0.15 to 0.17 second at the minimum, which cannot be further reduced.
Under these circumstances, it has been considered impossible to develop a superhigh-speed packaging apparatus having a capacity of manufacturing more than 6000 pieces of containers per hour, namely, 8000 pieces of containers per hour. In the conventional lateral seal bars, as shown in FIG. 1, an accommodation part 6 of the cutter blade 4 is disposed between sealing pressure receivers 5 made of rubber at one of the seal bars, and a cutter receiver 7 is disposed between the inductors 2 at the other of the seal bars. With such an arrangement, it is inevitable that a remaining part 8 (fluid remaining part) of the fluid content such as juice is produced in a groove defined between the accommodation part 6 and cutter receiver 7 while they are positioned in the heat seal part when subjected to heat sealing. Accordingly, fluid such as juice is stuck to the cutter when the web is cut, thereby permitting the cutter to be easily rusted when acid fluid such as juice is stuck to the cutter. As a result, nicks are produced on the cutter blade by the rust, which frequently causes the problem of insufficient cutting. Further, there occurs another problem that the machine is soiled owing to the flow of fluid from the cut part of the web and the production of rust at the mechanical parts caused by the acidity of the filled fluid. There occurs still another problem that a material employed by the mechanical parts is restricted.
In addition to the above problems, there frequently occurs a problem that the liquid in the fluid remaining part is stuck to the cut part of the web when the web is cut and mold is gathered from the cut part of the web, about which consumers make complaints. In case that the web is filled with a colored content, when the fluid permeates from the cut part into the web, there causes a problem of extreme damage of image of the product, and hence the cut part is printed by the same color as the filled content, making the cut part unobtrusive.
As mentioned in detail above, in the filling and packaging apparatus of this type, the fluid remaining part in the cutting part causes a serious problem to influence the quality of the packaged product. Accordingly, in the cutter which is disposed to freely advance and retreat and the lateral seal bars having grooves for accommodating the tip end of the cutter to prevent the sealed parts from producing the fluid remaining part at the center thereof, there are known a remaining product removing apparatus in which the cutter cuts the packaging material at the advancing position and it stays at a position where the tip end of the cutter presses the packaging material at the retreating position to prevent a remaining object or residue from being produced (as disclosed in JP-A 7-24938), and a sealing apparatus including a third heating mechanism provided at the upper and lower edges of the groove to accommodate the tip end of the cutter therein in addition to the upper and lower heating mechanisms in the lateral seal bars, wherein the residue produced at the time of sealing is sealed by the upper and lower heating mechanisms and the third heating mechanism (as disclosed in JP-A 7-164524). However, these apparatuses cannot completely prevent the production of a fluid remaining part because of the presence of the groove formed by the accommodation part and receiver part of the cutter.
The filling and packaging apparatus of this type is employed when manufacturing germ-free filling packs under a strict microorganic control. Since the filling and packaging apparatus must be sufficiently washed when the filling contents are changed or a daily working is finished, thereby limiting the operating time of the apparatus. Further, in view of the recent tendency of the shortage of working hours, the working efficiency and improvement of the working ratio, the development of the filling and packaging apparatus capable of being manufactured at higher speed has been desired.